08Cr2AlMo钢异种焊材熔焊接头中铁素体带形成温度的确定

Determination of the Ferrite Band Forming Temperature in 08Cr2AlMo Welded Joint with Dissimilar Welding Material

初步确定了 0 8Cr2AlMo钢的相变温度。通过热处理 ,在 0 8Cr2AlMo钢管材的异种焊材熔焊接头熔合区得到明显的脱 /增碳层 ,测定了接头中铁素体带形成的温度范围。实验发现 ,先共析铁素体是含铝钢焊接接头发生强烈碳迁移的主要条件。

Aluminium-bearing steel had strong corrosive-resistant capability and had been applied widely to petro-chemical industry recent years.But carbonmigration in welded joints restricted its application.The carbon migration always causes the forming of ferrite band structure.08Cr2AlMo steel pipe welded joints were aselected as the object of research.The phase-transformation temperature of this steel was determinded.By means of the individual heat-treatment,obvious carbon depleted/enriched zone were abtained in the fusion zone of 08Cr2AlMo pipe welded joints,with dissimilar material.Meanwhile the forming temperature range of ferrite band was measured.Results showed:The crystal structure difference between base and weld metal leads to the carbon migration.Carbon atom diffuse strongly from base metal to weld metal at about 800～850℃ in these joints.Proeutectoid ferrite plays the key role in the strong carbon migration of Al-bearing steel welded joints.